hey guys im curious how the IATs differ in the winter vs in the summer. I live in Albany new york where we have very cold winters. you think someone with an intercooler in florida will have lower IATs than me in the winter without an intercooler?

Without a doubt.I Live in south texas and the weather is is usually really hot and humid (upper 90s) Very similar to florida weather.When it gets cold down here usually around winter time,it gets into the 40s.Now I've personally monitored my IATs in both type of weather scenarios with a stock fmic and an upgraded fmic and found out that the upgraded fmic is gonna do better regardless.To give you an idea :

This past winter I had a stock fmic,in 40-50F weather my Starting IATs were around 90degrees,and upon WOT I would quickly get into triple digits with a highest of around 140F.Now since the air was very cool/cold,IATs would drop after a while.

Lets fast forward to now.I've upgraded my FMIC to an R.P.I and actually did some testing last night as a cold front blew thru and temps dropped into the mid 60s.For us in south texas thats a treat since its very hot all the time.Anyway,I quickly noticed my Starting IATs were 70 degrees and upon WOT would only go up about 10-15 degrees.I actually beat on the car quite a bit last night and went WOT 3-4 times and never once saw triple digits on my gauge.Keep in mind this is only mid 60 degree weather versus the factor fmic at 40-50 degrees.If you're curious about summer IATs.I typically see IATs cruising around at about 110 degrees.WOT i'll see them skyrocket and hit up to 140-150,but they come down really quickly too.The factory FMIC gets heatsoaked very easily regardless of how cold it is outside.Hope this helps.

Heat transfer efficiency is the key. And -20 will help, but still probably going to compare badly to an upgraded IC after many runs. That said, never done any -20 degree racing, hell most of the time the car won't start.

haha ya i guess my question is an intercooler in the summer vs. no intercooler in the winter which has lower aits?

Dont you mean intercooler in the summer vs factory intercooler in the winter ? cause if you think about it,all n54-powered vehicles have front mount intercoolers.Anyway,im sure being on the factory intercooler in -20F weather will have lower IATs than an upgraded factory intercooler in the summer.But keep in mind,regardless of the ambient temperature,the factory intercooler is gonna get heatsoaked much quicker under WOT.An upgraded FMIC is still the way to go.

I would say first a tune, then LSD, cat back-exhaust, IC, Intake, Charge pipe with BOV or DV, then Meth, in that order. Probably high flow catted down pipes are in there somewhere but personally I'm not going there. My 2 cents.

why what do you have installed there is no way you can reach that if you dont have meth so you must have meth. im assuming you have meth intercooler, tune and intake, am i right? (as your performance mods ofcourse)

John, the efficiency of the stock intercooler is what this all about regardless of anything else. The stock intercooler has an efficiency of about 50% and the upgraded ICs are at about 90%. That means they will cool much more effectively regardless of the temperature.

Second, the pressure drop across the stock IC is about 2 psi and around 0.5 psi on the upgraded ICs. This means, you turbos have to spin at lower RPMS to produce the same boost with the upgraded ICs.

The bottom line is the stock intercooler is a hunk of metal that absolutely needs to be replaced.

why what do you have installed there is no way you can reach that if you dont have meth so you must have meth. im assuming you have meth intercooler, tune and intake, am i right? (as your performance mods ofcourse)

Yes that would be with meth and not overdoing it on boost. I would like to keep it at a reliable. consistant performance level. I am doing the IC and Meth this fall. I had a baseline dyno of 280 rwhp and 321 when I added the Procede V1. Since then I had added most all but IC and meth. With the new Procede and those mods I think or my butt dyno feels like 340-350. I may indeed need to go to high flow cats but would rather not. I don't track the car just go fast now and then.

John, the efficiency of the stock intercooler is what this all about regardless of anything else. The stock intercooler has an efficiency of about 50% and the upgraded ICs are at about 90%. That means they will cool much more effectively regardless of the temperature.

Second, the pressure drop across the stock IC is about 2 psi and around 0.5 psi on the upgraded ICs. This means, you turbos have to spin at lower RPMS to produce the same boost with the upgraded ICs.

The bottom line is the stock intercooler is a hunk of metal that absolutely needs to be replaced.

not to mention that horrible restriction and baffling on the cold side stock FMIC connector... It just has to go (the whole FMIC).

John, the efficiency of the stock intercooler is what this all about regardless of anything else. The stock intercooler has an efficiency of about 50% and the upgraded ICs are at about 90%. That means they will cool much more effectively regardless of the temperature.

Second, the pressure drop across the stock IC is about 2 psi and around 0.5 psi on the upgraded ICs. This means, you turbos have to spin at lower RPMS to produce the same boost with the upgraded ICs.

The bottom line is the stock intercooler is a hunk of metal that absolutely needs to be replaced.

So for intercooler, is "efficiency" different from size? In my previous turbo car, upgrading to a bigger intercooler increased the turbo lag. Then people on the forums said that the theory was, you needed more air to fill up the bigger spaces in the intercooler/tubes to boost the turbo. I don't know.

Intercooler sizing is definitely going to affect its efficiency, but I think one thing not talked about here that is talked about in most other turbo forums is how much CFM the IC can flow. You also have to take into account the piping that goes along with that. Back when I had my Mitsubishi eclipse running very high boost (29psi) it wasn’t the amount of cooling that was the problem it was the ability to flow freely. I think it is pretty much the consensus that any aftermarket IC is better than the stocker, but what I would like to see from the venders is actual flow data showing not only the lower temps but the improved flow of air. The free smooth delivery of air has a tremendous impact on the performance of turbo cars. For the time being most of us are at pretty low boost scenarios (15-17psi) which in the turbo community is very mild. As we get the ability to do turbo upgrades we will find it necessary to have these free flowing IC and much better piping for them.

IAT is effected more by how hard you drive and heat soak the FMIC, then ambient temp.

Ehhh....that's not altogether true. You're going to have much lower IATs at a track day when it's 70F than when it's 90F, regardless of what i/c you have. Remember that how bad the i/c gets heatsoaked depends alot on ambient temp as well.

In my previous turbo car, upgrading to a bigger intercooler increased the turbo lag. Then people on the forums said that the theory was, you needed more air to fill up the bigger spaces in the intercooler/tubes to boost the turbo. I don't know.

GOOD question. I'm wondering the same thing as well but no one ever commented on this in here.

Can anyone of the guys that uses upgraded FMIC already to comment on this? Did they find more laggish behaviour after using a bigger IC?